EBV-HLH children with reductions in CD4+T cells and excessive activation of CD8+T cells

BACKGROUND: In this report, we analyzed the number and activation profiles of T cells in Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) patients and assessed their value for the diagnosis of EBV-HLH. METHODS: We compared the quantity of CD4+ T cells and CD8+ T cells in peripheral blood among HLH patients, a sepsis group, and healthy controls. We then analyzed variations in the activation marker in CD4+ T and CD8+ T cells. RESULTS: The percentage of CD4+ T cells decreased in the EBV-HLH patients when compared with healthy controls, which induced significant differences in the ratio of CD4+ T cells/CD8+ T cells. The percentage of CD4+ HLA-DR+ T cells, CD8+ CD69+ T cells, CD8+ HLA-DR+ T cells, and CD8+ HLA-DR+ T cells/CD4+ CD25+ T cells increased in EBV-HLH patients when compared with that in healthy controls. Compared with EBV-HLH survivors, the median percentage of CD4+ CD25+ T cells (7.9 vs. 3.0) were decreased, but the ratios of CD8+ HLA-DR+ T cells/CD4+ CD25+ T cells (6.3 vs. 20.3) were increased in the dead patients. CONCLUSIONS: There was a reduction in CD4+ T cells and abnormal activation of CD8+ T cells in the EBV-HLH patients. The percentage of CD4+ CD25+ T cells and the ratios of CD8+ HLA-DR+ T cells/CD4+ CD25+ T cells in EBV-HLH patients had a relation to the prognosis of the disease.